From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wolfgang Denk <wd@denx.de>
Date: Fri, 14 Oct 2011 23:42:16 +0200
Subject: [U-Boot] [PATCH v3 01/10] Add getenv_ulong() to read an integer
	from an environment variable
In-Reply-To: <1318626284-11161-1-git-send-email-sjg@chromium.org>
References: <1318610916-6975-2-git-send-email-sjg@chromium.org>
	<1318626284-11161-1-git-send-email-sjg@chromium.org>
Message-ID: <20111014214216.0461714094B2@gemini.denx.de>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

Dear Simon Glass,

In message <1318626284-11161-1-git-send-email-sjg@chromium.org> you wrote:
> This is not an uncommon operation in U-Boot, so let's put it in a common
> function.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
...
> +ulong getenv_ulong(const char *name, int base, ulong default_val)
> +{
> +	char buff[20];
> +	const char *str = NULL;
> +
> +	/*
> +	 * Prior to the import of the environment into the hashtable we
> +	 * should not call getenv()
> +	 */
> +	if (gd->flags & GD_FLG_ENV_READY)
> +		str = getenv(name);
> +	else if (getenv_f(name, buff, sizeof(buff)) > 0)
> +		str = buff;
> +	return str ? simple_strtoul(str, NULL, base) : default_val;
> +}

Sorry, I just changed my mind.

The issue with using getenv() before relocation is that it uses just a
tiny buffer (usually 32 bytes) in the global data structure to store
the result, which is often not sufficient for user provided data (some
boards have hwconfig strings that are _much_ longer than that, and
only the caller knows what to expect).

It's only now that I realize that we are dealing with int / long
values here only, so the length of the expected strings is indeed
limited - actually the buffer you provide here is way smaller that
what getenv() uses.

Can we please switch back to the previous version, but insert a
comment that explains why getenv_f() is not needed in this specific
case?

Thanks, and apologies for causing additional efforts.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Status quo. Latin for "the mess we're in."